The present study investigates the safety and efficacy of steroid withdrawal in pediatric renal transplant recipients with stable graft function under concomitant immunosuppression with cyclosporine and mycophenolate mofetil.

The present protocol aims to investigate the steroid-saving potential of MMF in pediatric patients after NTx. Over a 2-year period, two treatment regimes will be compared in randomized form in patients with a stable renal transplant function in the course of 12 - 24 months after transplantation (controlled first study phase):

Branch A: CyA + MMF + withdrawal of steroids over a three-month period following randomization

Branch B: CyA + MMF + 4 mg/m² methylprednisolone (or prednisolone equivalent)/day

After two years of observation, steroids in the control group (branch B) can be withdrawn optionally in conformity with the same protocol as in branch A (uncontrolled second study phase). It is to be expected that part of the patients will decide in favour of a withdrawal of steroids. In the uncontrolled second study phase, a comparison will thus be drawn among three therapy groups over a period of another 15 months (altogether 3.5 years beginning with randomization), in order to throw some light on the medium-term effect of steroid-free immunosuppression on length growth and transplant function.

Inclusion Criteria:

• Age < 18.0 years
• Bone age of boys < 15 years, of girls < 13 years
• Patients 12-24 months after renal transplantation with stable transplant function
• First or second kidney transplant, living or cadaver kidney donation
• Triple immunosuppression with cyclosporine (CyA), MMF, and daily steroids at study entry
• Patients and parents, respectively, have given their written consent after enlightenment (informed consent)

Exclusion Criteria:

• Irreversible rejection of former transplant within 6 months
• Highly reactive (> 80%) lymphocytotoxic antibodies within 12 months prior to transplantation
• Anamnestically steroid-resistant rejection of current transplant
• More than 2 acute rejection reactions prior to study entry (i.e., in the first 12-24 months after kidney transplantation) or 1 acute rejection reaction during the last 6 months before study entry
• Glomerular filtration rate (GFR) < 40 ml/min/1.73 m² (Schwartz formula) at study entry
• Acute rejection reaction or unstable transplant function (increase of serum creatinine > 20%) during the last 6 months before study entry or histologically confirmed chronic rejection reaction
• Suspected insufficient medication compliance
• Patients receiving a basic immunosuppression other than that prescribed in this protocol
• Simultaneous therapy with growth hormone after renal transplantation